ABSTRACT The Biostatistics Core facility provides the statistical and computational support for allGI cancer SPORE investigators. The Core will support consultation and collaboration on all aspects of study design, database development and quality control, and analysis and interpretation of data. The specific aims of this core facility are to: 1. Provide ready access to statistical expertise and computing consultation to the GI cancer SPORE program. 2. Provide biostatistical expertise for the planning, conduct, analysis and reporting of laboratory experiments, epidemiology studies and clinical trials. 3. Advise and support SPORE investigators and their data collectors (technicians, nurses, data managers, etc.) in the areas of data form design, data collection, record abstraction, computerization, database designing and management, and data qualitycontrol. Provide a scientific computing facility suitable to meet the statistical analysis of GI cancer SPORE investigators, including technical assistance in moving data between various computers and operating system environments.